diff --git a/numexpr/interpreter.cpp b/numexpr/interpreter.cpp
index 716d8ef..de4bf15 100644
--- a/numexpr/interpreter.cpp
+++ b/numexpr/interpreter.cpp
@@ -1203,7 +1203,7 @@ NumExpr_run(NumExprObject *self, PyObject *args, PyObject *kwds)
                 Py_INCREF(dtypes[0]);
             } else {  // constant, like in '"foo"'
                 dtypes[0] = PyArray_DescrNewFromType(NPY_STRING);
-                dtypes[0]->elsize = (int)self->memsizes[1];
+                PyDataType_SET_ELSIZE(dtypes[0], (npy_intp)self->memsizes[1]);
             }  // no string temporaries, so no third case
         }
         if (dtypes[0] == NULL) {
@@ -1449,7 +1449,7 @@ NumExpr_run(NumExprObject *self, PyObject *args, PyObject *kwds)
     /* Get the sizes of all the operands */
     dtypes_tmp = NpyIter_GetDescrArray(iter);
     for (i = 0; i < n_inputs+1; ++i) {
-        self->memsizes[i] = dtypes_tmp[i]->elsize;
+        self->memsizes[i] = PyDataType_ELSIZE(dtypes_tmp[i]);
     }
 
     /* For small calculations, just use 1 thread */
diff --git a/pyproject.toml b/pyproject.toml
index 3999a02..c57e423 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,7 @@
 [build-system]
-requires = ["setuptools", "wheel", "oldest-supported-numpy"]
+requires = [
+    "setuptools",
+    "wheel",
+    "numpy>=2.0.0rc1",
+]
 build-backend = "setuptools.build_meta"
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 1a276e7..6b5b554 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1 @@
-numpy >= 1.13.3
+numpy >= 1.19.3 # keep in sync with NPY_TARGET_VERSION (setup.py)
diff --git a/setup.py b/setup.py
index 74c3383..33fd31d 100644
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,10 @@
 inc_dirs = [np.get_include()]
 libs = []  # Pre-built libraries ONLY, like python36.so
 clibs = []
-def_macros = []
+def_macros = [
+    # keep in sync with minimal runtime requirement (requirements.txt) 
+    ('NPY_TARGET_VERSION', 'NPY_1_19_API_VERSION')
+]
 sources = ['numexpr/interpreter.cpp',
            'numexpr/module.cpp',
            'numexpr/numexpr_object.cpp']